System and method for controlling energy usage in a server

Abstract

A system for controlling energy usage in a server having a processor, where the system includes a memory for storing energy cost information, and a controller for determining a transaction rate for the processor. The controller is also for determining a cumulative of energy expended by the server based on the determined transaction rate for each of a number of available power level states (P-states) for operation of the processor, and for selecting one of the available P-states for operation of the processor based on the determined cumulative energy expended and the stored energy cost information.

What is claimed is: 
     
       1. A system for controlling energy usage in a server comprising a processor, the system comprising:
 a memory for storing energy cost information; and 
 a controller for
 determining a transaction rate for the processor, 
 for each of a plurality of available power level states (P-states) for operation of the processor, determining a cumulative of energy expended by the server based on the determined transaction rate, and 
 selecting one of the available P-states for operation of the processor based on the determined cumulative energy expended and the stored energy cost information. 
 
 
     
     
       2. The system of  claim 1  wherein the controller selects one of the available P-states for operation of the processor to substantially minimize a cost of the energy expended by the server. 
     
     
       3. The system of  claim 1  wherein the controller selects one of the available P-states for operation of the processor to substantially minimize a cumulative energy expended by the server. 
     
     
       4. The system of  claim 1  wherein the controller is further for selecting one of the available P-states for operation of the processor based on a user selected target computational throughput. 
     
     
       5. The system of  claim 1  wherein the stored energy cost information comprises an instantaneous energy cost. 
     
     
       6. The system of  claim 1  wherein the stored energy cost information comprises a fixed energy cost. 
     
     
       7. The system of  claim 1  wherein the stored energy cost information comprises a variable energy cost. 
     
     
       8. A method for controlling energy usage in a server comprising a processor, the method comprising:
 determining a cumulative of energy expended by the server for each of a plurality of power level states (P-states) available for operation of the processor; 
 selecting one of the plurality of P-states based on the determined cumulative energy expended and energy cost information; and 
 operating the processor in the selected one of the plurality of P-states. 
 
     
     
       9. The method of  claim 8  wherein the selected one of the plurality of P-states substantially minimizes a cost of the energy expended by the server. 
     
     
       10. The method of  claim 8  wherein the selected one of the plurality of P-states substantially minimizes a cumulative energy expended by the server. 
     
     
       11. The method of  claim 8  wherein selecting one of the plurality of P-states is further based on a user identified target computational throughput. 
     
     
       12. The method of  claim 8  wherein determining a cumulative of the energy expended by the server comprises determining a transaction rate for the processor. 
     
     
       13. The method of  claim 8  further comprising storing the energy cost information. 
     
     
       14. The method of  claim 8  wherein the energy cost information comprises an instantaneous energy cost. 
     
     
       15. The method of  claim 8  wherein the energy cost information comprises a fixed energy cost. 
     
     
       16. The method of  claim 8  wherein the energy cost information comprises a variable energy cost. 
     
     
       17. The method of  claim 8  wherein the server is one of a plurality of servers in a datacenter. 
     
     
       18. A non-transitory storage medium having computer executable instructions recorded thereon for controlling energy usage in a server comprising a processor, the computer executable instructions comprising instructions for:
 determining a cumulative of energy expended by the server for each of a plurality of power level states (P-states) available for operation of the processor; and 
 selecting one of the plurality of P-states for operation of the processor based on the determined cumulative energy expended and an instantaneous energy cost, wherein the selected one of the plurality of P-states is selected to substantially minimize a cost of the energy expended by the server. 
 
     
     
       19. The storage medium of  claim 18  wherein determining a cumulative of energy expended by the server for each of a plurality of P-states comprises determining a transaction rate for the processor. 
     
     
       20. The storage medium of  claim 18  wherein the instantaneous energy cost is variable.